Horton

Re: Performance degradation of REFRESH MATERIALIZED VIEW

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, Michael Paquier <michael@paquier.xyz>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Pavan Deolasee <pavan.deolasee@gmail.com>, Anastasia Lubennikova <a.lubennikova@postgrespro.ru>, Jeff Janes <jeff.janes@gmail.com>, Paul Guo <guopa@vmware.com>
Date: 2021-05-24T18:21:19Z
Lists: pgsql-hackers 
Hi,

On 2021-05-24 12:37:18 +0200, Tomas Vondra wrote:
> Another option might be changes in the binary layout - 5% change is well
> within the range that could be attributed to this, but it feels very
> hand-wavy and more like an excuse than real analysis.

I don't think 5% is likely to be explained by binary layout unless you
look for an explicitly adverse layout.


> Hmmm, thanks for reminding us that patch. Why did we reject that approach in
> favor of the current one?

Don't know about others, but I think it's way too fragile.

Greetings,

Andres Freund

Commits

  1. Fix pg_visibility regression failure with CLOBBER_CACHE_ALWAYS

  2. Revert most of 39b66a91bd

  3. Fix COPY FREEZE with CLOBBER_CACHE_ALWAYS